What's thong with that?

For decades, swimmers at public pools have had to observe a few simple rules: No smoking, no ducking, no petting, no running and no divebombing.

But it seems that anti-social behaviour in the 21st century has necessitated a radical updating of the familiar poolside poster.

The new version - unveiled yesterday - imposes a ban on the following: thongs and skimpy swimwear, body jewellery, lane rage, use of mobile phones and games consoles, snacking and drinking alcopops.

The regulations were drawn up after research among 500 leisure centre managers, who were asked to list the problems posed by thoughtless swimmers.

One of them was the time being wasted by lifeguards repeatedly having to pluck belly-button piercings from the bottom of the pool.

The new poster, complete with warnings on thongs, phones and jewellery, will be distributed to pools, leisure centres, health clubs and spas across the UK.

It was officially launched by the organisers of the Butlins Swimathon as part of a national campaign to improve bathers' etiquette. Former Olympic swimmer Duncan Goodhew, president of the Swimathon, said the survey of pool managers came about as safety regulations were being reviewed for the weeklong fundraising event.

'We were really expecting comments on nose-plugs and swimming caps,' he said. 'I was amazed to discover that pool managers actually have to ask swimmers to refrain from using their mobiles or games consoles on the water's edge.

'One swimming pool even caught a young female swimmer texting a friend details of a hunky lifeguard!'

He added: 'We are hoping the updated poster will enforce important safety messages at the same time as remaining fun.'

The poster replaces the one published in the 1970s by the Institute of Baths and Recreation Management.

A Swimathon spokesman said: 'It is clear from our research that it needs an update. Some bathers need pointing out that mobile phones, eating and skimpy swimwear don't belong in places of recreation.'

Martin Steer, education and training officer at the Institute of Sports and Recreation Management, said he had not heard of many complaints about thong-style swimwear.

But he added: 'Jewellery is certainly a nuisance because it comes off in the pool and lifeguards invariably have to dive in and retrieve it.'

While the poster has changed, the old rules still apply (although 'petting' has been changed to 'snogging').

'One of the biggest problems for lifeguards is still horseplay, such as running on the pool side, dive-bombing and ducking,' said Mr Steer.

The swimathon, taking place in March, aims to raise £2.5million for Macmillan Cancer Relief.